05-30-2019, 01:24 AM
(05-29-2019, 01:12 PM)vecnar Wrote: Hello Nikolay,
By continuity i meant small resistance i had on my multimeter which was done when everything was off. I do not have network analyzer.
Because you have none network analyzer you can't guess wither high freqency ground network conductivity is enough or not.
When integrating the board into the case, the developer need to ensure good ground contacts. It seems to me Pine64 efforts were not enough here.
Quote:Sbc doesn't have metal contacts on where screws attach. The only link between case and sbc was pcie bracket screw. So the link between sbc and hdd cages is through power cables, sata cables and sata controller mounting bracket.
This is called a "ground loop" and ia bad because makes the setup sensitive for electromagnetic interferences.
Ground loops should be as small as possible. To achieve that the chassis grounding should be performed at each interface or supply inlet.
I recommend you to try to tie all available ground surfaces of a board to the chassis.
Quote:You mentioned putting sata cables and power cables in one bunch but is it really a good idea to put power cables that have converter in them with data cables? Or should I place them as far apart as possible as it has voltage converter behind shrink wrap?
The SATA cable is shielded. Ts will not suffer from convertrer noise. But placing cables together you will decrease the ground loop cross-section thus will decrease inductance and high frequency impedance. It may make your sertup less suspectable to EMI.
Also when testing look into the logs for SATA errors. Thi interface may work in peesence of errors.